Checking the comments of a couple of posts, I noticed their lengths seem to be too uniform. E.g. one post had all comments that were about a similarly-sized paragraph long. Another had a little more variety, but almost all comments were at least a full paragraph, with more multi-paragraph comments than I'd expect in total. Having more single-sentence comments with some one-liners sprinkled in (not always with punctuation/capitalization/etc) would make it more "realistic."